Contraceptive Pearls
Foreskin and HIV
Q: What is it about the foreskin that might increase risk of HIV transmission?
A: The interior side of the foreskin has a mucosal surface, which is more susceptible to trauma than the tougher skin of the penile shaft or the glans. Moreover, the foreskin contains high levels of HIV target cells (such as Langerhan's cells). Indeed in a recent in vitro study of 14 foreskins, investigators from Chicago found that foreskin mucosal tissue had a 7-fold greater susceptibility to HIV-1 than cells in cervical tissue under the same conditions. Lastly, the presence of a foreskin appears to increase risk of ulcerative sexually transmitted diseases such as chancroid and herpes, which are strong co-factors for HIV infection.
Thus there appears to be good biologic plausibility to the epidemiologic finding that male circumcision reduces risk of HIV infection.
References
- Estrada CR et al. Biologic mechanisms of HIV infection of human foreskin: implications for transmission. Presentation at the American Urological Association, May 2002.
- Szabo R, Short R. How does male circumcision protect against HIV infection? BMJ 2000; 320:1592-1594.
- Moses S, Bailey RC, Ronald AR. Male circumcision: Assessment of health benefits and risks. Sex Transm Infect 1998; 74:368-73.
Male Circumcision and National HIV Infection Rates
Q: Does the prevalence of male circumcision (MC) help explain why HIV is increasing rapidly in some countries, but not in others?
A: Probably so, though such cross-country comparisons are tricky and involve other factors. Notably, HIV has increased most rapidly in Eastern and Southern Africa where MC is uncommon (e.g., Botswana, Zimbabwe, Zambia, Malawi, Rwanda, Swaziland.) In contrast, although HIV probably originated in West Africa, HIV prevalence there tends to be much lower and MC tends to be very common.
Of course MC is very common in Islamic countries, and Islamic faith might also relate to lower behavioral risk of HIV. However, some countries are not predominantly Islamic but have high MC rates and comparatively low HIV (e.g., Philippines, Ghana, Benin, Nigeria, Liberia, Gabon, Madagascar).
In other countries the pattern seemingly doesn't support the argument. For example, Kenya has high overall circumcision and relatively high HIV (though HIV is notably high among the Luo, the only major ethnic group that doesn't practice circumcision). Latin America and Europe have low HIV even though male circumcision is not common.
Reference
- Halperin DT and Bailey RC. Male circumcision and HIV infection: 10 years and counting. Lancet 1999; 354:1813-15.
Demand for Male Circumcision
Q: I can see that there might be some health benefit from male circumcision, but is there significant demand for it from men?
A: Yes, several studies from Africa at least, indicate that demand for circumcision among uncircumcised men is substantial. Interestingly, the demand appears to be largely for reasons of "hygiene," cleanliness and prevention of local infections/sexually transmitted infections and not particularly for reduced risk of HIV specifically. Female partners also appear to support circumcision for similar reasons.
References
- Soori N et al. Dynamics of male circumcision practices in Northwest Tanzania. STI 2001; 28:214-8.
- Bailey RC et al. The acceptability of male circumcision to reduce HIV infections in Nyanza Province, Kenya. AIDS Care 2002; 14:27-40.
- Kebaabetswe P et al. Male circumcision: An acceptable strategy for HIV prevention in Botswana. Unpublished manuscript (Also Abstract accepted for 2002 Barcelona AIDS Conference.)
- Fritz K et al. The feasibility of adult male circumcision for HIV prevention in Zimbabwe. (Submitted)
These “Pearls” are prepared by Dr. James D. Shelton, Senior Medical Scientist, Office of Population, United States Agency for International Development (USAID). June-July 2002.
